@jwz Strange that you couldn't find a source as per the article. Goes to show compartmentalised Google results for different languages are. I found two in Dutch from the same local (provincial) broadcaster, one already linked in the thread but that wasn't about greenhouses. This one is, and it's from half a year earlier, May 2022 https://www.omroepbrabant.nl/nieuws/4085845/zo-wordt-een-bitcoin-computer-gebruikt-om-bloemen-te-kweken
And a third one from the "Flowers & Plants News" trade publication, about a test of the same thing from Nov 2017! https://www.bpnieuws.nl/article/8013058/welke-tuinder-wil-er-in-de-bitcoins/